You may be passing sensitive vars to your terraform commands. If you do not want
the terraform commands to display in your drone logs then set sensitive to true.
The output from the commands themselves will still display, it just won’t show
what command is actually being ran.

You may want to run terraform against internal resources, like an internal
OpenStack deployment. Sometimes these resources are signed by an internal
CA Certificate. You can inject your CA Certificate into the plugin by using
ca_certs key as described above. Below is an example.

You may want to assume another role before running the terraform commands.
This is useful for cross account access, where a central account has privileges
to assume roles in other accounts. Using the current credentials, this role will
be assumed and exported to environment variables.
See the discussion in the Terraform issues.

You may want to change directories before applying the terraform commands.
This parameter is useful if you have multiple environments in different folders
and you want to use different drone configurations to apply different environments.

You may want to only target a specific list of resources within your terraform
code. To achieve this you can specify the targets parameter. If left undefined
all resources will be planned/applied against as the default behavior.

You may want to limit the number of concurrent operations as Terraform walks its graph.
If you want to change Terraform’s default parallelism (currently equal to 10) then set the parallelism parameter.